BACKGROUND: Significant delay can occur between the first dose of a long-acting injectable (LAI) antipsychotic and achievement of efficacious plasma concentrations, which is usually addressed by supplementing with oral antipsychotics or administering an LAI loading dose. A 1-day initiation regimen is now available as an alternative to 21 days of oral aripiprazole supplementation (21-day initiation regimen) for starting treatment with aripiprazole lauroxil (AL). The regimen utilizes a single injection of a nano-crystalline milled dispersion of AL (AL-NCD; ARISTADA INITIO[TM]) and a single 30 mg dose of oral aripiprazole.
METHODS: A double-blind, randomized, pharmacokinetic (PK) and safety study compared the 1-day and 21-day initiation regimen for starting AL treatment. Population PK model–based simulations, together with observed data, were used to evaluate the relative contributions of each of its components.
RESULTS: The PK and safety profiles of the 1-day and 21-day initiation regimens were comparable. Aripiprazole concentration–time profiles demonstrated that each component delivered aripiprazole to the systemic circulation at different time periods, with the 30 mg dose of oral aripiprazole predominant in the first week, followed by AL-NCD, and then AL.
CONCLUSIONS: The 1-day initiation regimen was well-tolerated and a suitable alternative to the 21-day initiation regimen for starting AL. Each component of the 1-day initiation regimen, together with AL, is necessary to provide continuous coverage from treatment initiation until the next regularly scheduled AL injection.